WebKit, as used in Apple iTunes before 12.3, allows man-in-the-middle attackers to execute arbitrary code or cause a denial of service (memory corruption and application crash) via vectors related to iTunes Store browsing, a different vulnerability than other WebKit CVEs listed in APPLE-SA-2015-09-16-3.
https://support.apple.com/HT205265
https://support.apple.com/HT205221
http://www.securitytracker.com/id/1033617
http://www.securityfocus.com/bid/76765
http://lists.apple.com/archives/security-announce/2015/Sep/msg00007.html
http://lists.apple.com/archives/security-announce/2015/Sep/msg00003.html